1. Field of the Invention
This invention relates to an image processing device employed in the likes of a hardness testing device and a method of image processing.
2. Description of the Related Art
A hardness testing device that measures hardness of a measuring object based on a shape of an indentation formed in a surface of the measuring object, is known (refer to JP 2010-190817 A and JP 2005-345117 A). In this hardness testing device, the measuring object is disposed on a stage and a measured value of hardness of the measuring object is obtained using an image of the measuring object capable of being taken by an imaging device. When the image shows only a region of part of the measuring object, an entire image showing the measuring object is necessary. Thus, conventionally, a method that shifts the stage relatively in a certain direction to take a plurality of images and joins these plurality of images to generate a composite image, is known (refer to JP H08-313217 A).
However, in the above-described method for generating a composite image, if directions of coordinate axes of the image and directions of coordinate axes of the stage are not in parallel, then in a portion where the image is joined, the composite image becomes discontinuous and errors are generated in coordinate values of the image in a coordinate system of the stage. This problem is solved if an attitude of the imaging device is physically adjusted such that directions of the coordinate axes of the image and the coordinate axes of the stage are matched. However, that adjustment is laborious and adjustment costs are also required.
The present invention was made in view of such a problem and has an object of providing an image processing device and a method of image processing capable of generating a composite image having no discontinuity at a composite portion, easily and at low cost.